Flow charts and workflow diagrams are commonly used to design or analyze automated processes. In some cases (e.g., automated prepress systems, robot control systems) the diagram itself is the finished workflow. A workflow diagram may be drawn by hand, in which case some form of data entry is required to convert it to machine-readable form. This may involve redrawing the diagram and reentering the data if there are any substantial changes. There are systems that allow a diagram to be drawn on a computer, typically by dragging and dropping shapes (representing workflow or flow chart nodes) into place, and then connecting them by dragging lines from one shape to another, but these systems can be cumbersome to use.